1. Field of the Invention
The present invention relates to a mixing element for use in a static type motionless fluid mixer having not a mechanically movable portion, for mixing one and more kinds of fluids (liquid, gas, and powder and particle substance), and relates to a method of producing the same.
2. Description of the Relevant Art
The static type fluid mixer of this kind is used as, for example, a treatment apparatus by a gas absorption reaction of a harmful material such as HCl, Cl.sub.2, NO.sub.x, SO.sub.x and the like in a waste gas, an organo-chloric compound removing apparatus by an aeration treatment of a waste water including an organo-chloric compound such as trichloroethane, methylene chloride, trihalomethane and the like in the waste water, otherwise a dust removing (dust collecting) apparatus of SiO.sub.2 dust and the like exhausted from a semiconductor factory and an optical fiber producing factory. Also, the static type fluid mixer is used in many fields such as the chemical industry, the paper and pulp industry, the food industry, the fermentation industry, the civil engineering and construction industry, the plastic industry and the pollution prevention industry and the like.
This static type fluid mixer is constituted by disposing in a pipe a plurality of blades connected to each other, each of the blades being twisted spirally. During two and more kinds of fluids which are different in characteristic from each other flow in the fluid mixer, the fluid advances spirally through passages partitioned by the blades, and is divided at boarders of respective blades, and further is joined to the divided fluids passing through the other passages (for example, U.S. Pat. No. 4,408,893). And, the fluid is agitated and mixed by a repeat of the division and the joining.
The fluid includes a liquid, a gas or a powder and particle substance, and, as different characteristics of the fluid, there are a viscosity, a composition, a temperature, a color, and a particle size. This fluid mixer can mix the fluids which are different in phase, such as a mixing of a gas and a liquid.
Such a fluid mixer is used as means for a mixing, an agitating, a dispersion, an emulsification, an extraction, a heat exchanging, a reaction, a gas absorption and a dilution and the like, in the above mentioned fields.
Moreover, as a method of producing the fluid mixer, there is a method of inserting spiral blades of a right-handed twisting or a left-handed twisting in a pipe, and fixing adjacent blades to each other by welding and brazing and the like (Japanese Patent Publication (KOKOKU) 44 -8290). And, there is a technique of inserting spiral blades of a right-handed twisting or a left-handed twisting in a pipe, and engaging or fitting adjacent blades with each other to disposing them in a pipe (West Germany Laid Open No. 2262016). Further, there is a method of inserting spiral blades of a right-handed twisting or a left-handed twisting in a pipe while disposing supporting pieces between the adjacent blades, thereby fixing and connecting the blades by the supporting pieces (U.S. Pat. No. 3,953,002). Furthermore, there is a method of inserting baffle plates twisted on the right-handed side or on the left-handed side into a tubular housing, and engaging with each other concave grooves formed on protrusions of both ends of the baffle plate to thereby connect them (Japanese Patent Publication (KOKOKU) No. 1 -81928). Furthermore, there is proposed a fluid mixer in which baffle plates are formed by arranging narrow portions of band-like members at predetermined pitches, twisting wide portions of the band-like members spirally and in a clockwise direction or an anti-clockwise direction, and twisting the narrow portions by about 90.degree., and then the baffle plates are inserted into a pipe (U.S. Pat. No. 4,408,898).
However, the above mentioned respective fluid mixer all have drawback in which the producing thereof is not easy.
Particularly, there are drawbacks in which the connecting portions of the blades i-s weak in mechanical strength in a case where the blades are welded or bladed to each other (Japanese Patent Publication (KOKOKU) No. 44 -8290), and the welding portions are broken or snapped in a case where the twisting stress is added thereto.
Also, there is a drawback in which the connection portion of the baffle plates is weak in twisting stress and easy to be broken in a case where the baffle plates are spot-connected to each other at center portions thereof (U.S. Pat. No. 4,408,893).
And, this fluid mixer has a drawback in which the mixing effect in a laminar flow region of a high viscosity fluid.
Further, as described above, each of the conventional fluid mixers has the drawbacks in which the producing cost is expensive due to the difficulty of producing thereof and the mixing effect is low.